Sound-producing device



I Apl il 7, 1931.

J P. NORTHEY SOUND PRODUCING DEVICE Filed June 16, 1930 Patented Apr. 7,1931

unit

mages JOI-IN 3?. ZNOBTHEY, 0F TORONTO, ONTARIO, CANADA SOUND-PRODUCING nnvrcn Application filed June 16, 1930. Serial No.461 ,478.

slocession of puffs to :produce a musical note.

As the driving of the piston required air at high pressure, a somewhat-expensive air compressing and cooling system has heretofore been necessary to provide and store such air,

and the 'objectof the present invention is to so construct the device that air at'a materially 7 lower pressure may be employed to actuate the piston giving the same stroke as'formersly; or ifthe same pressure as former'lyis 29 used a longer stroke and reduced air consumption in the speaking end of the piston will be obtained.

' In the-earlierconstructions the hollow piston was provided with an enlarged head op- -,erating in a separate chamber or cylinder of greater diameter than that of the-sound producing cylinder and the control ofthe drivin-g air was effected solely by ports in the enlarged piston head and its cylinder wall.

The air passages were thus of neces'sityof small cross sectional area relative to their length so that frictional losses iii-the air were high and lag in transmission so great that high air pressures were essential.

In my co-pending application No. 343,817,

I show a construction which enabled me to materially reduce the pressure of the driving air and. secure :a greater length of stroke than was previously possible. This result was attained by providing supplemental inlet and exhaust ports controlled by the parts of the piston and cylinder of smaller diametenthe supplemental exhaust being through the piston wall into the interior of the hollow pis- 43 ton.

It has been found, byfurther experiment, that it is possible to re-arrange the port system shown in the said application to'permit of a further reduction of the pressure of the driving air and to secure even greater length cylinder end.

of stroke for a given air pressure; This result I attain by means of the constructions hereinafterspecifically described but which. may be briefly outlined as follows Provie sions are made for combining the outlets of the exhaust systems sothat'the exhaust may be controlled, as, for example, by connecting it with an exhaust pump. Further, as in tlre present invention the drivingair will or may be at a lower pressure than the sound-producing air, I have provided means for using the pressure of the soundproducing air to check the back strokeof the piston andto initiate the forward-stroke.

The invention is'illustrated in the raccompanyi-ng drawings inWhich- Fig. 1 is a sectional detail of parts of the apparatus showing the piston in the exhaust position; I i v i F g. 2 a similar View showing the piston in the position in which the driving air is admitted behind it; and V r Fig. 3 a detail in elevation of part of the In the drawings like numerals of reference indicate correspondinglparts in the difl'erent figures. i

1 is the casing in which is mounted a cylinder 2. The wall of this cylinder has a series of sound producing orifices 3 formed therein which will usually be spacedat equal distances apart. Within the cylinder a hollow piston 4 is adapted to reciprocate, this piston being alsoprovided withgsound prog ducing orifices 5 adapted to be brought into alinement with the orifices in the cylinder by the reciprocation of the'piston.

The piston is provided with an enlarged head 6 adapted to reciprocate'in the cylinder enlargement .7 The apertured part of the piston isseparated from the remainderof the piston by the diaphragm 8. The open end of the piston communicates with; the horn 9, which is suitably securedto the end of the casing. y

Within the casing-is formed the chamber 10 communicating with the air inletll. The sound is produced by the reciprocation i of i the pist.on,'which causes its sound producing orifices to coincide at regular intervals with the orifices of the cylinder 2, thus producing a series of puffs of air which occur at such intervals as to form a musical note.

The piston and casing are constructed in the following manner to effect the reciprocation of the piston. The cylinder enlargement 7 is provided with the annular ports 12, 13, which are connected by a plurality oflongitudinal passages 25. In the wall of the cylinder enlargement is also formed an annular port 14 with which communicate a plurality of radial passages 15 which com municate with an annular chamber 16 formed in the cylinder enlargement 7. With this chamber communicates the air inlet 17. Intermediate the ports 12 and 13 is an annular exhaust port 18 with which communicate a plurality of radial passages 19 which communicate with an annular chamber 20 formed between the casing and the cylinder enlargement. The piston head has an annular groove 23 formed in its exterior surface, which is so positioned that. when it forms a communication between the exhaust port 18 and the port 13, the port 2 is uncovered. Also through the head of the piston are formed aplurality of passages 24 opening through the forward face of the piston head and through its periphery. Preferably the innerparts of these passages are formed by an annular groove in the exterior surface of the piston head.

1 Assuming the other ports shown in the drawings are omitted, it follows from the construction described that, when the parts fare in the position shown in Fig. 1, air from behind the piston head is exhausted through the port 12, the longitudinal passages 25, the port 13, the groove 23, the exhaust port 18, the passages 19, .and the chamber 20, The momentum of the piston then carries it a little further to the right. There is then the condition that air under pressure is acting on the front of the piston while the pressure has been exhausted from behind. The piston is, then forced to the position shown in Fig. 2 in which the groove 23 no longer forms a communication between the port 13 and the exhaust port 18. In this position the port 13 is still open to the space behind the piston head while the passages 2 1 provide a passage for air from the space in front of the piston head through the port 13, passages 25 and port .12 to the space behind the piston heal. The same air pressure then exists both in front of and behind the piston head, but, owingto the greater surface of the piston head exposed to air pressure at the back than at the front, the excess pres sure drives the piston forward to and beyond the exhaust position previously described.

The piston is thus reciprocated to effect sound production as hereinbefore described. The parts previously described are old in the art. but to them I have now added the following features of construction to give a supplemental exhaust and air admission for the driving of the piston. In the cylinder wall 1 form an annular supplemental exhaust port 23 with which communicate a series of radial passages 27 communicating with an annularchamber 33 formed between the casing and the cylinder wall. The annular passages 20 and 33 are connected at one side of the device with a common outlet 34. Formed in the wall of the piston is an annular port 28 which communicates with a series of longitudinal passages 29 formed in the wall of the piston and opening through its rear end. hus part of the exhaust takes place directly from the passages 25 through the port 18, the radial passages 19 to the annular chamber 20, while another portion passes through the passages 29, the port 28 and the radial passages 27 to the annular chamber 33. The chambers 20 and 33 having a common outlet, any desired control means may be applied to the exhaust, as, for example, by providing means to choke the exhaust and create back pressure, or by applyin suction to the outlet to increase the rapidity of the exhaust and thus increase the piston stroke.

A supplemental path for air under pressure is provided through the medium of the supplemental inlet port 30 formed in the cylinder wall and the radial passages 31 formed in the cylinder wall and communicating with the chamber 16. In the piston wall is formed an annular port 36 communicating with the passages 29 and adapted to register with the supplemental inlet port 30 when the port 24 is admitting air to the port 13.

V] hen the driving air pressure is reduced much below that of the sound-producing air, it may be found that the return stroke of the piston is insuliiciently cushioned. I therefore provide means for using the high pressure air to cushion the back stroke and initiate the forward'movement of the piston. For this purpose I provide the annular port 32 in the wall of the cylinder communicating with the radial passages 3a which in turn communicate with the longitudinal passages 35 leading to the chamber 10 into which the driving air is introduced. It w'll be noted that on the return stroke of the piston the port 36 first registers with the port 30 to admit driving air behind the piston and that a continuation of the return movement under the influence of momentum will cause the port 28 to register with the port 32 to admit the sound producing air behindthe piston and check its rearward movement. The piston then moves forward to and past the position shown in Fig. 2, in which the ordinary driving air is admitted behind the piston both by the ports of the piston and cylinder, and the ports of the piston and cylinder enlargements, and to the. exhaust position shown in Fig. 1. The pressure behind the piston is then exhausted both through the ports (of the piston and cylinder and the ports of the piston and cylinder enlargements and the cycle rccommences.

IJfind that with'th'e new construction driving air may be employed at :a lower vpressure even than that of the sound producing lair,

thus not only efi'ecting economies in operation but also in theenpense-of anstallat1on, or asan alternative a longer stroke maybe obtained by using the higher pressures now .commonlyemployed.

What I claim as any invention :is

1. A sound producing device comprising a cylinder having soundproducing orifices in its wall; a hollow piston adapted to recipro-' :Crlllfi.lllSftlClCYllllClGli, open at one end and hav-' :piston .headand the wall of the cylinder en-.

largement controlling the admission and exhaust ort the spistondriving lil'll'.; an exhaust :port in the cylinder; a passage in the cylinder wall forming a communication between the last mentioned portand an exhaust out let; a port in :the pistonwalli; and a passage leading from said part through the piston to the back thereof, whereby air :is exhausted through the cylinder wall :at the 'endof the forward stroke as well as through the cylinder enlargement. r

2. .A sound producing device comprising .a cylinder ihaving sound producing orifices in its wall; .a hollow pistonzadapted to reciprocate in said cylinder, open at one end and having sound producing eriliccs in its wall adapted "to be brought into alinement with the orifices in the cylinder by the ireciprocation oi the piston; an enlarged head at the end of the piston remote from its open end an enlargement of the cylinder in which the piston head reciprocate's; v.ports' in the piston head and the wall of the cylinder en'- lar-gement controlling the admission and lexhaust of the pistondri'ving air; and co-opersting ports, :and passages in rthe cylinderand piston wallsatorming an exhaust supplcmen- 'tal to that ot thie piston headand cylinder enlargement and discharging independently through the cylinder wall. I

. 73. A sound producing device comprising a cylinder having sound producing orifices in its wall; a hollow piston adapted :to reciprocate in said :cylinder, open at one end and having sound producing orifices in its wall adapted to be brought into alinement with the orifices in the cylinder by the reciprocation of the piston; an enlarged head at the endo't the piston remote from its open end;

an :ienla-rgement of the cylinder in which the pistonlheadreciprocates; ports in the piston head and the wall of the cylinder enlargement controlling the admission andnexhaust otthe piston driving ziirpco-operating ports and passages in the. cylinder'and piston walls storming an exhaust supplemental to that of the piston head and cylinder enlargement and discharging independently through the cylinder wall; and a casing formed with a v chamber coupling the exhaust outlet of thecylinder enlargement and the supplemental exhaust outlet of the cylinder,

4;. A sound, producingldevice comprising a cylinder havingsound producing orificesin its wall; a hollow pistonadapted to reciprocate in said cylinder, open at one end and having sound producing orifices in its wall adaptedto be brought into alinement with the orifices in the cylinder by the reciprocation of the piston; an enlarged head at the end of the piston remote from its openend;

an enlargement 0f the cylinder :in which the piston head reciprocates; an'air inlet and'an air outlet in said enlargement; ports in the piston head and the wall of :the cylinderen- 'largement controlling the admission and exhaust-ofthe piston driving airf; aninlet port o in the cylinder wall ;'a passage in the cylinder wall forming a communication between the.

last mentioned portand-an inlet of the drivin -air'a ort in the iston wall "and-a eas sage leading tromsaid-port through the piswtont'o theback thereof, whereby driving air maybe admitted through the-piston wall-as 3' well as through the cylinder enlargement.

5; A sound producing device comprising a cylinder having sound producing orifices in its wall ,a hollowpistion adapted to "reciprocaLe in said cylinder, open at one end and having sound producing orifices in its wall adapted to be brought into alinement with the orifices in the cylinder by the reciprocation of the piston; an enlarged head at the end of the pistonremote'from its open end;

an enlargement of the cylinder in which the piston head 're'ciprocates; an air inlet and an an outlet in said enlargement; ports in the piston head and the wall of the cylinder en Largemen't controlling the admission and eX- 'haust otthe piston :drivingair an inlet port in thecyllnder wall; a passage in the cylinder wall formlngz a communication between the lastmentioned port and an inlet of the driving air; aport in the piston wall; a

passage leading from said port through the piston to' the back thereof, whereby driving air may be admitted through the piston wall as well as through the cylinder enlargement; a second air inlet port in the cylinder wall; a

passage in theicylinder'wallleading to the outside thereof; and a second port' in the piston wall leading to the longitudinal pas sage of the piston wall,;the lastmentioned ports ot'the piston and 'cylinderbeing posi- E tioned to come into co-operation on the return stroke of' the piston after the previously mentioned ports of the piston and cylinder.

6. A sound producing device comprising a cylinder having sound producing orifices in its wall; a hollow piston adapted to reciprocate in said cylinder, open at one end and having sound producing orifices in its wall adapted to be brought into alinement with the orifices in the cylinder by the reciprocation of the piston; an enlarged head at the end of the piston remote from its open end; an enlargement of the cylinder in which the piston head reciprocates; an air inlet and an air outlet in said enlargement; ports in the piston head and thewall of the cylinder enlargement controlling the admission and ex haust of the piston driving air; an inlet port in the cylinder wall; a passage in the cylinder wall forming a communication between the last mentioned port and an inlet of the driving air; a port in the piston wall; a passage leading from said port through the piston to the back thereof, whereby driving air may be admitted through the piston wall as Well as through the cylinder enlargement; a second air inlet port in the cylinder wall; a

passage in the cylinder wall leading to the outside thereof; a second port in the piston wall leading to the longitudinal passage of the piston wall, the last mentioned ports of the piston and cylinder being positioned to come into co-operation on the return stroke of the piston after the previously mentioned ports of the piston and cylinder; an exhaust port in the cylinder; and a passage in the cylinder wall forming a communication between said port and an exhaust outlet, one of the ports in the piston wall'being adapted to register with the said exhaust port at the end of the forward stroke of the piston.

7. A sound producing device comprising a. cylinder having sound producing orifices in its wall; a hollow piston adapted to reciprocate in said cylinder, open at one end and having sound producing orifices in its wall adaptedto be brought into alinement with the orifices in the cylinder by the reciprocation of the piston; a chamber in the device for the sound-producing air supply; an enlarged head at the end of the piston remote from its open end; an enlargement of the cylinder in which the piston head reciprocates; an air inlet and an air outlet in said enlargement; ports in the piston head and the wall of the cylinder enlargement controlling theadmission and exhaust of the piston driving air; and supplemental ports and passages in thestationary and movable ports for admitting air from the sound producing air supply of the apparatus to the space behind thepiston at or about the end of the return stroke.

8. A sound producing device comprising a cylinder having sound producing orifices in its wall; ahollow piston adapted to reciprocate in said cylinder, open at one end and having sound producing orifices in its wall adapted to be brought into alinement with the orifices in the cylinder by the reciprocation of the piston; a chamber in the de vice for the sound-producing air supply; an enlarged head at the end of the piston re mote from its open end; an enlargement of the cylinder in which the piston head reciprocates; an air inlet and an air outlet in said enlargement; ports in the piston head .and the wall otthe cylinder enlargement controlling the admission and exhaust of the piston driving air; and supplemental ports and passages in the piston and cylinder Walls for admitting air from the sound producing air supply of the apparatus to the space behind the piston at or about the end of the return stroke.

9. A sound producing device comprising a ylinder having sound producing orifices in its wall; a hollow piston adapted to reciprocate in said cylinder, open at one end and having sound producing orifices in its wall adapted to be brought into alinement with the orifices in the cylinder by the reciprocation of the piston; a chamber in the device for the soundproducing air supply; enlarged head at the end of the piston remote from its open end; an enlargement of the cylinder in which the piston head rcciprocates; an air inlet and an air outlet in said enlargement; ports in the piston head and the wall of the cylinder enlargement controlling the admission and exhaust of the piston driving air; supplemental ports and passages in the stationary and movable ports for admitting air from the sound producing air supply of the apparatus to the space behind the piston at or about the end of the return stroke; and supplemental ports and passages in the piston and cylinder walls for admitting supplemental driving air to the space behind the piston at the same time that the ports of the piston head and cylinder enlargement are admitting driving air thereto.

10. A sound producing device comprising a cylinder having sound producing orifices in its wall; a hollow piston adapted to reciprocate in said cylinder, open at one end and having sound producing orifices in its Wall adapted to be brought into alinement with the orifices in the cylinder by the reciprocation of the piston; a chamber in the device for the sound-producing air supply; an enlarged head at the end of the piston remote from its open end; an enlargement of the cylinder in which the piston head reciprocates; an air inlet and an air outlet in said enlargement; ports in the'piston head and the wall of the cylinder enlargement controlling the admission and exhaust of the piston driving air; supplemental ports and passages in the stationary and movable ports for admitting air from the sound producing air supply of the apparatus to the space behind the piston at or about the end of the return stroke; and supplemental exhaust ports and passages in the piston and cylinv der Walls adapted to exhaust air from behind the piston at or about the same time that exhaust is taking place through the ports of the piston head and cylinder enlargement. V

11. A sound producing device comprising a cylinder'having sound producing orifices in its Wall; a hollow piston adapted to reciprocate in said cylinder open at one end and having sound producing orifices in its Wall adapted to be brought into alinement With the orifices in the cylinder by the reciprocation of the piston; means for admitting and exhausting piston driving air from the cylinder; means for admitting soundproducing air to the eXteriorof the part of" the cylinder provided With the sound pro-s ducing orifices; and means, controlled by the piston for admitting sound producing air behind the pistonat or about'the end of its stroke in one direction.

Signed at Toronto, Canada, this 3rd day of June, 1930.

' JOHN P. NORTHEY. 

